The present invention relates generally to the field of pressure washers. More specifically, the present invention relates to a pressure washer water pump and a crankcase of a small engine used to power the pump.
A pressure washer includes a water pump powered by a small, internal combustion engine. The engine includes an engine block having internal chamber, such as a crankcase, in which a piston drives a crankshaft. The piston and crankshaft are lubricated by motor oil, and if the engine is a vertically-shafted engine, typically the oil pools in a cover (e.g., a sump) forming a base of the crankcase. The engine may be mounted to a base plate of a wheeled support frame. A power takeoff end of the crankshaft extends through an opening in the crankcase, and then through the base plate to engage the water pump.
The water pump typically includes a housing mounted to the underside of the base plate. Typically inlet and outlet pipes extend from the water pump beneath the base plate. To use the pressure washer, a garden hose is attached to the inlet pipe, and a pressure washer spray gun is coupled to a high-pressure hose line attached to the outlet pipe of the pump. Within the housing, the pump includes a pumping mechanism for driving the flow of water.